Application of fragrance to fabric substrates using foam

ABSTRACT

A method of applying fragrance to a fabric substrate includes bleaching a cotton fabric substrate, mercerizing the cotton fabric substrate, and preparing the cotton fabric substrate for dyeing. The method includes making a foam containing a bonding material made of an acrylic polymer or a carboxylated, heat-reactive, styrene-acrylic copolymer, a surfactant, water, and microcapsules of a fragrant material in a ratio of about 40% bonding material, about 2% surfactant, about 45% water, and about 13% microcapsules of a fragrant material. The cotton fabric substrate is passed through a foam applicator where the foam is applied to the cotton fabric substrate using a top applicator of a foaming machine to apply the foam to a face of the fabric substrate in a wet-pickup range of 25% to 10%.

BACKGROUND OF THE INVENTION

Aromatherapy is a popular trend and been found to be beneficial for many people. That benefit could be extended with a fabric with infused scents that will remain in the fabric after several washings: a lavender-infused fabric for bed sheets, for example. Numerous attempts at achieving that or a similar result can are found in the art and cluster among two ways of obtaining such a fabric. One way is to finish a woven or knitted fabric by an application of a substance that adheres to the fabric and gives off the aroma in the final product. The other way is to make (spin) a synthetic fiber, and cache the fragrant compound within the fiber (such as by locating it in voids within the fiber). That fiber is used to make a yarn, and then weave or knit the yarn into the fabric form. But success has been elusive. The fragrance is present in or attached to the fabric as a finite quantity of the substance that has aroma (fragrance source), and the sensation of smelling the fragrance occurs as molecules of the substance emanate from the fabric to the nose of the person experiencing the fragrance. That process inherently depletes the quantity of the fragrance source over time, until the number of molecules that can emanate becomes so small that the fragrance experience is diminished or lost. Laundering, as in a home laundry, can wash out some or all of the fragrance and accelerate the loss of fragrant effect.

SUMMARY OF THE INVENTION

The present invention addresses one or more of those needs in the art by providing a fragrant fabric comprising a fabric substrate and microcapsules of a fragrant material adhered to the fabric substrate with an acrylic or acrylic-styrene copolymer formulation. The fabric substrate may be cotton, such as a preshrunk, 4.2 oz./sq. yd. (142.4 gm/sq. meter), 100% Combed Cotton.

The microcapsules may be adhered to the fabric substrate with a carboxylated, heat-reactive, styrene-acrylic copolymer or a high-solids, self-crosslinking, acrylic polymer.

Preferably, the fabric substrate is preshrunk woven cotton and the microcapsules are adhered to the fabric substrate with a high-solids, self-crosslinking, acrylic polymer.

The invention can be considered as a fragrant fabric made by passing a woven cotton fabric substrate through a foam applicator, and applying a foam to the fabric substrate in the foam applicator, and drying the fabric. The foam includes acrylic polymer, microcapsules containing a fragrant material, a surfactant and water.

The invention can also be considered as a method of applying fragrance to a fabric comprising providing a fabric substrate, providing a foam containing an adhering material and microcapsules of a fragrant material, passing the fabric substrate through a foam applicator, applying the foam to the fabric substrate in the foam applicator, and drying the fabric substrate and foam.

Providing a fabric substrate may include providing a woven cotton fabric substrate. Providing a fabric substrate may include bleaching a cotton fabric substrate, mercerizing the cotton fabric substrate, and preparing the cotton fabric substrate for dyeing.

Applying the foam to the fabric substrate in the foam applicator may include applying the foam using a top applicator of a foaming machine to apply the foam to a face of the fabric substrate. Applying the foam to the fabric substrate may include applying the foam in a wet-pickup range of 25% to 10%

Providing a foam may include providing a foam with a bonding material, a surfactant, water, and microcapsules of a fragrant material. The bonding material may be a carboxylated, heat-reactive, styrene-acrylic copolymer. The bonding material may also be a high solids, self-crosslinking acrylic polymer emulsion. Applying the foam may be at 15% wet pickup, a blow ratio of 15-20, and drying may be at 230° F. (110° C.). The surfactant may be an amine oxide.

The bonding material, surfactant, water, and microcapsules of a fragrant material may be present in the foam in a ratio of about 40% bonding material, about 2% surfactant, about 45% water, and about 13% microcapsules of a fragrant material.

DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION

The fabric substrate can be made by weaving, knitting (circular knit or warp knit) or otherwise manipulating the yarn or fibers to form a fabric substrate.

A cotton fabric substrate can be used. In one example, a cotton sheeting fabric substrate is prepared for dyeing, bleached, and mercerized (PFGD). PFGD fabric substrate is available with a thread count of 78 x 76 yarns per inch (30.7 x 29.9 yarns per cm), and the fabric substrate is approximately 44 to 45 inches (111.8 to 114.3 cm) wide and shrinks to approximately 41 to 42 inches (104.1 to 106.7 cm) wide when washed. A particular sheeting, PFGD, is preshrunk 59 inch (149.9 cm) 4.2 oz./sq. yd. (142.4 gm/sq. meter), white, 100% Combed Cotton.

The fragrance is applied to the PFGD fabric substrate as foam in a foam applicator. The foam applicator is available as a Chemical Foam System from Gaston Systems, Inc. of Stanley, North Carolina and includes a generator and an applicator. The generator is used to mix the items to go into the foam, and the applicator has a pathway for a fabric substrate that exposes the fabric substrate to foam from the generator that is applied to the fabric substrate as it passes through the applicator.

A foam applicator that may be suitable for use is available from Prism Textile Machinery of Gujarat, India, which sells wide range of foaming equipment to companies who wish to finish fabrics using foam technology.

One embodiment of the foam uses a formulation of an acrylic polymer bonding material, microcapsules of fragrance, a surfactant that helps with frothing, and water. The acrylic polymer bonding material may be Unibond 1779, available from Unichem, Inc. of Haw River, North Carolina. UNIBOND 1779 is a high-solids, self-crosslinking, acrylic polymer emulsion.

Typical Properties of Unibond 1779 Total Solids 59.0% pH 3.5 Viscosity (Brookfield) 100 cps. Chemical Nature Anionic Tg (°C) -26 Density (lbs./gal.) 8.8 (1.05 gm/ml)

Another embodiment of the foam uses a formulation of a styrene-acrylic copolymer bonding material, microcapsules of fragrance, a surfactant that helps with frothing, and water. The styrene-acrylic copolymer bonding material may be Unibond 1919, available from Unichem, Inc. of Haw River, North Carolina. UNIBOND 1919 is a carboxylated, heat-reactive, styrene-acrylic copolymer emulsion. Films of UNIBOND 1919 are very soft and exhibit excellent resistance to discoloration. These films are also characterized by their superior water resistance. Unibond 1919 itself is 45%-55% of a styrene-acrylic copolymer and 55%-45% water.

Typical Properties of Unibond 1919 Total Solids 50% pH 3.5 Viscosity (2@60) 450 cps. Particle Charge Anionic Tg (°C) -12 Density (lbs./gal.) 8.8 (1.05 gm/ml) Specific Gravity 1.15

Another formulation uses Unibond 1919-SC, which is also available from Unichem and which is a 45-55% styrene-acrylic copolymer and 45-55% water. It is 48.5-51.5% solids, has a pH of 2.5 -5.0, density of 8.3-9 lbs/gal (0.99 gm/ml -1.08 gm/ml), and a viscosity < 1000 cP.

Typical Properties of Unibond 1919-SC Total Solids 50% pH 2.5 Viscosity (2@60) 400 cps. Particle Charge Anionic Tg (°C) -12 Density (lbs./gal.) 8.8 (1.05 gm/ml) Specific Gravity 1.15

Other suitable bonding materials or agents can be used.

A suitable surfactant is Unifroth 1942, also available from Unichem. Unifroth 1942 is a surfactant designed for use as a non-rewetting wetter at low levels, or as a foaming agent at higher levels. The non-rewetting nature comes from its ability to degrade under drying or curing temperatures. This property allows the fabric to both wet-out thoroughly in the application bath and yet have no residual surfactant properties left after drying and curing. Unifroth 1942 is a clear liquid with an activity of33.0 %, a pH of 7.0 to 8.5 and is completely soluble in water. Other suitable surfactants can be used.

The foam is generated using less water than conventional processing. Air is introduced, creating the bubbles in the foam. The foam also includes the scent microcapsules. The microcapsules can be sourced commercially. The foam application method replaces traditional water-based application methods and is more energy efficient than the water-based finishing and application.

The foam can be applied to the fabric substrate in a top applicator of the foam applicator, and various wet-pickups can be used, such as 10% to 25%. Once the foam has been applied to the fabric substrate, they are dried, such as at 230° F. (110° C.).

Samples were made using Unibond 1779 and Unibond 1919-SC. The foam was made up of 45% water, 40% bonding material (either Unibond 1779 or Unibond 1919-SC), 13% lavender microcapsules and 2% Unifroth 1942. The samples were made by applying the foam at 15% wet pick up and a blow ratio between 15 and 20. The drying temperature of the fabric substrate after foam application was 230° F. (110° C.).

The resulting samples were tested for wash fastness, using AATCC 135 test procedure, with AATCC 1993 WOB as the detergent. The samples yielded these results:

Unibond 1919-SC Unibond 1779 Initial Strong lavender scent Strong lavender scent After 5 launderings Slight fresh scent Slight fresh scent After 10 launderings Slight fresh scent Slight fresh scent After 15 launderings Slight fresh scent Slight fresh scent After 20 launderings Slight fresh scent Slight fresh scent After 25 launderings Slight fresh scent Slight fresh scent After 30 launderings No scent Slight fresh scent After 36 launderings Slight fresh scent

The method can be used with a range of fabric substrates, and the parameters such as the binders may change. Various fabric substrates with various scents can be used, such as rose-scented wool blankets, lavender-scented underwear, among many others. Various fibers can be used in the fabric substrate, including wool, wool-blends, cotton, cotton-blends, polyester, rayon, nylon, polyester, spandex, elastomers, acrylic, rayon, ramie, silk, bamboo, linen, sisal, viscose, flax, hemp, jute, and mixtures or blends thereof.

The scents can be made available as essential oils, some of which are thought to have anti-microbial properties. Among the scents that may be desirable are honey, peach, pear, apple, and ingredients used in perfumes such as aldehydes, Ambergris, Balsam, Civets, Eugenol, Hydroxy citronellal, Ionones (aroma compounds found in a variety of essential oils, including rose oil), Musk, and Rhizomes. Additional scents that may be suitable for inclusion as fragrance sources are listed in Tables 1-4 .

Table 1 Major Essential Oils and Effects on the Body Systems that have been mentioned in the art: Essential Oils Effects Basil Uplifting, refreshing, clarifying, aids concentration Chamomile Refreshing, relaxing, calming, soothing, balancing Cedarwood Sedating, calming, soothing, strengthening Clary Sage Warming, relaxing, uplifting, calming, causes euphoria Cypress Relaxing, refreshing, provides astringent qualities Eucalyptus Head clearing, provides antiseptic and decongestant properties, Fennel Provides relief from gas and indigestion Frankincense Relaxing, rejuvenating, eases breathing, dispels fears Geranium Refreshing, relaxing, balancing, harmonizing Hyssop Provides decongestant properties Jasmine Relaxing, soothing builds confidence Juniper Refreshing, stimulating, relaxing, promotes diuresis Lavender Refreshing, relaxing, provides therapeutic qualities, calming, Lemon Refreshing, stimulating, uplifting, motivating Lemongrass Toning, refreshing, fortifying Marjoram Warming, fortifying, sedating Melissa Uplifting, refreshing Myrrh Toning, strengthening, rejuvenating, provides expectorant Neroli Relaxing, dispels fear Orange Refreshing, relaxing Patchouli Relaxing, enhancing to sensuality Peppermint Cooling, refreshing, head-clearing Petitgrain Refreshing, relaxing Pine Refreshing, provides antiseptic properties, invigorating, stimulating Rose Relaxing, soothing enhances sensuality, builds confidence Rosemary Invigorating, refreshing, stimulating, clarifying Sandalwood Relaxing, arming, builds confidence, grounding Tea Tree Acts as antiseptic, strengthens immune system Thyme Acts as antiseptic, refreshing, strengthens, immune system Ylang-ylang Relaxing, soothing, enhances sensuality

Table 2 The Sedative Effects/or Emotions of Essential Oils that have been mentioned in the art: Emotion Essential Oils with the Sedative Effects Anxiety Benzoin, Lemon, Chamomile. Rose, Cardamom, Clove, Jasmine Lament Rose Stimulation Camphor, Balm oil Anger Chamomile, Balm oil, Rose, Ylang-ylang Wretchedness Basil, Cypress. Mint, Patchouli Allergy Chamomile, Jasmine, Balm oil Distrustfulness Lavender Tension Camphor, Cypress, Vanilla. Jasmine. Balm oil. Lavender, S l l l Melancholy Basil, Lemon, Chamomile, Vanilla, Jasmine, Lavender, Mint, B Hysteria Chamomile, Balm oil, Lavender, Jasmine Mania Basil, Jasmine, Pine Irritability Chamomile, Camphor, Cypress, Lavender Desolation Jasmine, Pine, Patchouli, Rosemary

Table 3 The Pharmaceutical Effects of Essential Oils that have been mentioned in the art: Effects Essential Oil Sedation Mint, Onion, Lemon, Metasequoia Coalescence Pine, Clove, lavender, Onion, Thyme Diuresis Pine, lavender Onion. Thyme, Fennel, Lemon, Metasequoia Facilitating Menses Pine, lavender. Mint, Rosemary, Thyme, Basil, Chamomile, Cinnamon, Lemon Dismissing sputum Onion, Citrus, Thyme, Chamomile Allaying a fever Ginger, Fennel, Chamomile, Lemon Hypnogenesis Lavender, Oregano, Basil, Chamomile Curing Hypertension Lavender. Fennel, Lemon, Ylang-ylang Be good for stomach Pine, Ginger, Clove, Mint, Onion, Citrus, Rosemary, Thyme, Fennel, Basil, Cinnamon Diaphoresis Pine, lavender, Rosemary, Thyme, Chamomile, Metasequoia Expelling wind Ginger, Clove, Onion, Citrus, Rosemary, Fennel, Lemon Losing weight Onion, Cinnamon, Lemon Relieving pain Vanilla, lavender. Mint, Onion, Citrus, Rosemary, Chamomile, Cinnamon, Lemon Detoxification Lavender Curing diabetes Vanilla, Onion, Chamomile, Lemon Stopping diarrhea Vanilla, Ginger, Clove, lavender. Mint, Onion, Oregano, Rosemary, Thyme, Chamomile, Cinnamon, Lemon Curing flu Pine, lavender, Mint, Onion, Citrus, Rosemary, Thyme, Chamomile, Cinnamon, Metasequoia Curing Lavender, Onion, Citrus, Rosemary, Thyme, Metasequoia Urging sexual passion Pine, Ginger, Clove, Mint, Onion, Rosemary, Thyme, Fennel, Relieving spasm. Cinnamon Promoting appetite Clove, lavender, Mint, Onion, Citrus, Rosemary, Fennel Basil, Chamomile, Cinnamon, Lemon, Metasequoia Relieving cough Rosemary

Table 4 Aroma categories: Citrus Lemon (Citral, Citronellal), Orange (Mandarin Oil, Decyl acetate) Floral Carnation (Phenethyl salicylate), Gardenia (Nonyl acetate), Geranium (Citronellol), Lilac (Anisyl acetate), Lily (hydroxycitronellal), Rose (Rose Fruity Apple (Benzyl acetate), Apricot (Allyl butyrate), Banana (Amyl acetate), Grape Herbaceous Clove (Eugenyl acetate), Minty (1-carveol, 1-Carvone, 1-Menthol) Sweet Anise (Ethyl acetate, Methyl sorbate), Cinnamon (Cinnamaldehyde), Honey

Sources of the fragrances, aromas and scents mentioned in tables 1-4 may be suitable for use as the fragrance.

Other textile products can be made in accordance with the invention. One example is towels, such as face towels and bath towels. Another example is woolen blankets. Apparel fabric substrates can also be made. For example, undergarments can be provided with a scent. Scents can be scents conventionally known for use in aromatherapy, or can be perfume-like scents or functional scents such as insect repellents (DEET or permethrin) or antimicrobials. The added material can be cannabidiol (CBD). Silver can be added to fibers or filaments to act as an antimicrobial, such as is done by the technology of PurThread Technologies, Inc. of Cary, North Carolina, disclosed in U.S. Pat 9,878,480 and 9,908,987. Those fibers or filaments can be positioned as desired in the fabric substrate.

The microcapsules need not be homogeneous, but could be a mixture of microcapsules to provide multiple properties. Microcapsules that will fracture differently under different conditions can be used together, so that some fracture and release their contents at one time, and others at another time, to provide a timed-release effect.

Instead of adding microcapsules with fragrance to the sheets that go on the bed, the microcapsules can be added to the mattress ticking that covers the mattress. There are several benefits to this approach. The adhesive materials in the foam can be much more aggressive in holding the microcapsules to the fabric substrate, since there is less need to be as concerned about having a good resulting “hand.” In use, people do not come into contact with the ticking, so if the ticking feels tacky or harsh, that is of much less concern than if the fabric is the bedsheet. Since the ticking is almost never washed, there is less need for wash fastness. Also, in use the mattress is usually covered with a mattress pad, sheets, etc. so the rate of transfer of the fragrance to the atmosphere is inhibited, slowing the depletion of the reservoir of fragrance on the ticking.

Certain modifications and improvements will occur to those skilled in the art upon reading the foregoing description. It should be understood that all such modifications and improvements have been omitted for the sake of conciseness and readability but are properly within the scope of the following claims. 

What is claimed is:
 1. A fragrant fabric comprising a fabric substrate and microcapsules of a fragrant material adhered to the fabric substrate with an acrylic or acrylic-styrene copolymer formulation.
 2. A fragrant fabric as claimed in claim 1 wherein the fabric substrate is cotton.
 3. A fragrant fabric as claimed in claim 1 wherein the fabric substrate is preshrunk 4.2 oz./sq. yd. (142.4 gm/sq. meter), 100% Combed Cotton.
 4. A fragrant fabric as claimed in claim 1 wherein the microcapsules are adhered to the fabric substrate with a carboxylated, heat-reactive, styrene-acrylic copolymer.
 5. A fragrant fabric as claimed in claim 1 wherein the microcapsules are adhered to the fabric substrate with a high-solids, self-crosslinking, acrylic polymer.
 6. A fragrant fabric as claimed in claim 1 wherein fabric substrate is preshrunk woven cotton and the microcapsules are adhered to the fabric substrate with a high-solids, self-crosslinking, acrylic polymer.
 7. A fragrant fabric made by passing a woven cotton fabric substrate through a foam applicator; applying a foam to the fabric substrate in the foam applicator, the foam including acrylic polymer, microcapsules containing a fragrant material, a surfactant, and water; and drying the fabric.
 8. A method of applying fragrance to a fabric comprising providing a fabric substrate, providing a foam containing a bonding material and microcapsules of a fragrant material, passing the fabric substrate through a foam applicator, applying the foam to the fabric substrate in the foam applicator, and drying the fabric substrate and foam to yield a fabric substrate with adhered microcapsules of fragrant material.
 9. The method as claimed in claim 8 wherein providing a fabric substrate comprises providing a woven cotton fabric substrate.
 10. The method as claimed in claim 8 wherein providing a fabric substrate comprises bleaching a cotton fabric substrate, mercerizing the cotton fabric substrate, and preparing the cotton fabric substrate for dyeing.
 11. The method as claimed in claim 8 wherein applying the foam to the fabric substrate in the foam applicator comprises applying the foam using a top applicator of a foaming machine to apply the foam to a face of the fabric substrate.
 12. The method as claimed in claim 8 wherein applying the foam to the fabric substrate comprises applying the foam in a wet-pickup range of 25% to 10%.
 13. The method as claimed in claim 8 wherein providing a foam comprises providing a foam containing a bonding material, a surfactant, water, and microcapsules of a fragrant material.
 14. The method as claimed in claim 13 wherein the bonding material is a carboxylated, heat-reactive, styrene-acrylic copolymer.
 15. The method as claimed in claim 13 wherein the bonding material is a high solids, self-crosslinking acrylic polymer emulsion.
 16. The method as claimed in claim 13 wherein applying the foam is at 15% wet pickup, a blow ratio of 15-20, and drying is at 230° F. (110° C.).
 17. The method as claimed in claim 13 wherein the surfactant is an amine oxide.
 18. The method as claimed in claim 13 wherein the bonding material, surfactant, water, and microcapsules of a fragrant material are present in the foam in a ratio of about 40% bonding material, about 2% surfactant, about 45% water, and about 13% microcapsules of a fragrant material.
 19. A method of applying fragrance to a fabric substrate comprising bleaching a cotton fabric substrate, mercerizing the cotton fabric substrate, and preparing the cotton fabric substrate for dyeing, making a foam containing a bonding material made of an acrylic polymer, a surfactant, water, and microcapsules of a fragrant material, wherein the bonding material, surfactant, water, and microcapsules of a fragrant material are present in the foam in a ratio of about 40% bonding material, about 2% surfactant, about 45% water, and about 13% microcapsules of a fragrant material, passing the fabric substrate through a foam applicator, and applying the foam to the cotton fabric substrate in the foam applicator using a top applicator of a foaming machine to apply the foam to a face of the fabric substrate in a wet-pickup range of 25% to 10%, and a blow ratio of between 15-20, and drying the cotton fabric substrate and foam. 